Hypodermic syringe and barrel blank



May 2s, 1957 H, Q MOUNA, Re'. 24,322

I HYPODERMIC SYRINGE AND BARREL BLANK l Original Filed May 2G, 1952 I BY INVENTOR. mfg (7.' 1101121411 M ,6h-4.4,. g/H

#from/Frs 'Henry G. Molinari,

United l States Patent Office 24,322 HYPODERMIC SYRINGE AND BARREL BLANK Rutherford, N. I assignor to Becton Dickinson and Company, Rutherford, N. I., a corporation of New Jersey Original No. 2,776,661, dated January 8, 1957, Serial No. 288,780, May 20, 1952. Application for reissue March 4, 1957, Serial No. 643,901

Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification;.matter printed in italics indicates the additions made by reissue.

This invention relates to a structurally and functionally improved hypodermic syringe assembly as well as a barrel blank to be employed in providing such assembly.'-

The present application is a continuation-in-part of my prior case on Syringe Barrel and Machine and Method for Forming the Same filed in the United States Patent Office on .lune 12, 1948, and identified under Serial Number 32,660 of which a continuing application resulted in U. S. Patent No. 2,684,556.

By means of the present invention a furnished which is ideally suited for use in connection with the machine and method as taught in my prior [application] patent; this blank being capable of being employed by relatively unskilled labor to provide a unit in a syringe assembly of superior type.

lt is a further object of the invention tofurnish a syringe assembly which will meet all standards of the medical profession and which may be subjected to'repeated cleaning and sterilizing operations, involving the use of detergents, without the assembly being detrimentally affected. A

A further object is that of furnishing a hypodermic syringe in which the danger of squirt backs is avoided in that the parts-while being freely movable with respect to each otherwill have cooperating characteristics permitting of the ejection of highly uid medicaments despite the fact that objectional leakages are prevented.

An additional object is that of providing an assembly which will have a long effective life and which may be largely produced by automatic machinery and methods with minimum of manual supervision and final inspections.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating one practical embodiment of the invention and in which:

Fig. 1 is a side elevation of a complete assembly;

Fig. 2 is a sectional side view of a barrel blank or preform;

Fig. 3 is a similar view but showing the barrel in substantially completed condition; and

Fig. 4 is a side elevation of a plunger constructed in accordance with the present teachings and for use with lthat barrel.

Referring primarily to Fig. l, the numeral 5 indicates a glass syringe barrel within the bore of which a plunger 6 may be reciprocated. In accordance with conventional techniques, the rear of this plunger preferably vterminates in a portion 7 suitable for engagement with the thumb or finger of the operator. The opposite end of the syringe barrel terminates in a tip 8. This tip conveniently mounts a fitting 9 embracing any suitable structure by means of which a hypodermic needle (not shown) may be supported on the tip. The face of the syringe preferably includes suitable indicia 10 in the form of subdivisions barrel blank is i Reissued May 28, 1 957 2 indicating cubic centimeters and fractions thereof. The indicia may obviously additionally include anyother desired data. l

In accordance with the present invention the syringe barrel is formed from a blank or preform of -glass. That preform embraces as shown in Fig. 2 a body lllhaving adjacent one of its ends a closing wall continued in the form of a tip 12. As indicated in Fig. 2, this-tip 'may be sealed or else open. Adjacent its opposite end the blank is preferably formed with an outstanding ange portion 13. The body 11 of the preform may contain 4minute air bubbles 14 as an incident to the initial formation of the blank. The bore 15 of the preform may be relatively rough or irregular although to assure a maximum production of perfect units it should be as nearly truly cylindrical as is practicable. Conveniently this bore is ared adjacent its rear or open end as indicated'at 16. It is continued at its forward end in a passage or bore 1'1 extending into the tip 12. As afore brought out, that tip may either be open or sealed as indicated in Fig. 2.

After this preform has been -mounted upon the mandrel of the machine and subjected to the forming operations as taught in my prior [application] patent, itsbore is decreased .in diameter. Likewise, its external diameter may be somewhat decreased. This has been indicated in Fig. 2 by the dot and dash lines which show the final dimensions in comparison with the full lines. For purposes of illustration, the differences in dimensions have been somewhat exaggerated as has also the showing of irregular surfaces defining the bore 15. In any event, and as illustrated in Fig. 3, a barrel 5 is produced which adjacent its open or rear end preferably includes a flange 13 with the'bore flared adjacent this flange as at 16. The air bubbles 14 will remain within the body of 'the unit in that no grinding is necessary in accordance with'the method which is practiced. Therefore, these air bubbles will not be in effect opened by the action of the grinding tool resulting in what is commonly known as -airlines which might render the syringe barrel unsuitable for use. Rather, the bore remains smooth and uninterrupted and presents a chill surface throughout its length. In other Words, this surface will embody the characteristics of what might be termed very hard veneer. That surface will be quite hard and resist to a maximum extent .any erosive action by strong concentrations of detergents or other substances. Thus, there is produced bythe machine and method traversed in my earlier application a syringe barrel which requires only the application of a fitting to its tip if such a fitting is necessary.

To complete the assembly the plunger is produced. That plunger is again formed completely of glass. It is preferably provided by associating a suitably semi-completed unit with a centerless grinder so that the body of the piston or plunger has the lines of grinding and lapping extending transversely of the plunger axis. These lines define peak portions and valleys ofmcroscopc dimensions. [Throughout its forward area] Throughout the forward area 0f the plunger, indicated at 18 in Fig. 4a bearing surface is furnished which is as nearly truly cylindrical as is feasible and includes a micro-finish (one in which the peaks and valleys of the linesV of -grind a flange adjacentoneend of said a closed end of said bore :forming Van be reoiprocated within the bore of the barrel in a relatively free manner, but at the same time the length of the I seal area will prevent leakage. Also, due to this effec- Atitre area, even when the plunger is .repeatedly .subjected to the-action of detergents, yit will Anot lbe .affected :detrimentally. -The tapered nature of area 19 assures that fthe-plunger will freely ride within the `bore of the barrel.

V:The -forward end of the `plunger is preferably Jtapered Kas' indicated at 20. A line .or other indicating mark .271 {may Zbe incorporated in 'this end portion. .The walls of the-barrel being transparent, the line will be readily visible Athrough Vsuch walls. Therefore, a physician `may .align the end ofthe plunger with Vthe desired unit orsubdivision A-and be 'assured -that thesyringe contains just the desired volumeofmeiiicament to be injected.

-The Vplunger will have a free, sliding action `within the barrel bore. The seal provided between the ground and lapped surface ofthe plunger and the smooth, clean bore "facewill be extremely effective. -It 'will assure a proper fexplusion of liquid fcontained in the barrel as the A,plunger is projected. `Due to the character of the cooperating .-'surfacesthere'will be-no danger of objectionable rearward leaks or squirt-backs between the barrel and plunger surfaces. .This will also be assured by the increased area #of the seal between these parts. Additionally, as a con- `sequence 'of the increasein-sealing area of the plunger .or l'piston the surface of the 4latter will not be rendered ineffective even when repeatedly subjected to the action of concentrated detergents. Therefore, the effective life of the assembly will be much greater than has heretofore been ythe case.

Thus, among others, the several objects of :the invention as specifically aforenoted are achieved. Obviously, nu- -merous changes in construction and rearrangement of fthe parts might :be resorted to without departing from ithe spirit of the invention as defined by the claims.

r1. A syringe barrel blank for application to a barrel- ,shrinking machine in which the bore diameter `of said Ablankis decreased, the 'blank diameter is decreased -and the length of said blank remains `substantially unchanged, .said lblank including va tubular body of axlength'substantiallyfequal to :that .to be embraced Ain the fnishedfbarre'l, said body having 'an unground, substantially cylindrical `bore 'having relatively y'raised and lowered portions on its surface, the 'diameter of such bore being substantially largerthan thatyto be incorporated in thefinished syringe,

body and extendingout- AWardly therefrom, end -wall closing the opposite end .of said lbody and a needle 'mounting ktip extending beyond said end wall.

2. A syringe barrel blank vfor application to la barrel* 4shrinking machine yin which the bore diameter of said Iblank is decreased, the 'blank diameter is decreased -and the length of said blank remains substantially unchanged, .fsai'd blank including a tubular :body of a length substan- =tiall-y equal to that 'to bejembraced in thefinished barrel, said body having an unground, substantially cylindrical bore/having relatively raised and lowered portions on its "surface, the diameter of such bore being substantially :larger than that to be incorporated in the-finishedsyringe, '-a ange adjacent one end of said body and extendngout- 'wardly therefrom, a closed end of said 'bore forming an l'end wall closing the vopposite end of said body, a needle vmounting tip extending beyond said end wall, =said ytip i being formed with a passage and material integral Vwith said'tip for sealing thefoutter end of said passage.

3. A syringe assembly including in combination` a barrel presenting a smooth fan-d cylindrical unground bore uniform diameter throughout its effective length to thus embrace in the bore face a smooth uninterrupted surface [embracing peak portions and valleys] and a plunger reciprocable in said bore and having a lapped cylindrical bea-ring surface embracing peak portions-and valleys ,cooperating with the -inner surface of said barrel, thepeak portions yof the grind in such surface being in sealing contact with said bore surface.

4. A syringe assembly including in combination a Vbarrel presenting a smooth and cylindrical ungroundbore of uniform diameter throughout `its veffective length to thus embrace in the bore face a smooth uninterrupted surface [embracing vpeak portions and valleys] and a plunger reciprocable in said bore and having a lapped cylindrical bearing surface embracing peak portions and va'lleys `cooperating with the inner surface of said barrel, the fpeak portions of the grind in such surface being .in sealingcontact with said bore surface, said lines of grind extending .transversely to ythe `axis .of said plunger.

v5. A syringe assembly including in combination a barrel presentinga smooth and cylindrical unground bore of uniform .diameter throughout its effective length to thus =embnace in the bore face a smooth uninterrupted surface [embracing peak yportions and valleys] and a plunger reciprocable in said bore and having a lapped cylindrical .bearing surface `en'zbracing peak portions'and 'Valleys c0- operating with the inner surface of said barrel, the peak v portions ofthe grind insuch surface being in sealing contact with said bore surface, and the length of said bearing surface lbeing ,not less than ten percent of the effective length of said plunger. y 6. .A :syringe y'assembly including lin combination abarrel presenting a smoothfand cylindrical unground bore .of uniformdiameter throughout its effective length to thus .embrace `inthe bore face a smooth uninterrupted surface -[embracing peak portions and valleys] and --a plunger ireciprocableinsaidbore and presenting a-lapped cylindri- 'cal bearing surface-embracing peak portions and valleys, the peak portions of the grind in such surface being in .sealing .contact .with ysaid "bore surface and the effective 'length-of said hearing surface being substantially thirty ,percent ofthe effective length of said plunger.

l7. Asyringe .assembly including Yin combination a barrel presentingva Icomplet'ely smooth and cylindrical bore of uniformdiameter throughout its effective length -to thus embrace in the bore face a smooth uninterrupted surface, a plunger `having :an inner end reciprocable in said bore .and shaving a lappedcylindrical bearing surface'embracingpeak ,portions and valleys, the peak portions of the grind in such surface extending transversely of lthe iplungeraxis and'being in sealing contact :withsaidzbore surface adjacent the inner plungerend and the effective length oftsaid `bearing surface being substantially thirty percent'of the effective length of said plunger.

References Cited in the file of this patent .or the i original .patent UNITED STATES PATENTS 772;'450 Wulfing-Luer Oct. 18, 1904 '1,863,785 vrDickinson I une 2l, 1932 2,392,104 Smith Ian. l, 1946 f v 2,641,093 LKolodnyct al. June 9, 1953 vvFOREIGN PATENTS 52,130 GreatBritain Jan. 30, 1908 

